Fas is a cell‐surface protein which belongs to the tumor‐necrosis‐factor‐receptor family. Signals through Fas are able to induce apoptosis in sensitive cells, and thus modalities for regulating the level of Fas expression on tumor cells are needed. We have studied cellular responses to gamma irradiation. The level of p53 tumor‐suppressor protein was found to be elevated 3 hr after irradiation of p53wild‐type MCF‐7 breast‐carcinoma cells. Interestingly, accumulation of p53 was followed by up‐regulation of surface Fas levels between 4 and 8 hr after irradiation. The level of Fas up‐regulation was dependent on dose and, whereas elevation in the level of p53 was transient, enhancement of Fas expression was stable. Fas up‐regulation occurred coincidentally with induction of G1 cell‐cycle arrest, a post‐irradiation phenomenon known to be dependent on wild‐type‐p53 activity. We studied 9 other tumor lines, 2 with wild‐type p53, 5 with mutant p53, and 2 expressing no p53. All lines expressing wild‐type p53 were found to arrest in G1 and to up‐regulate Fas after irradiation. In contrast, all 7 p53null and p53mutant lines failed not only to arrest their cell cycles in G1 phase, but also to up‐regulate Fas levels in response to treatment. These findings demonstrate a direct correlation between wild‐type‐p53 activity and Fas up‐regulation after treatment with ionizing radiation, strongly suggesting that post‐irradiation Fas up‐regulation is dependent on wild‐type‐p53 activity. Since low doses of radiation were sufficient to modulate Fas expression, up‐regulation of the Fas death receptor may have clinical implications following radiotherapy. Int. J. Cancer 73:757–762, 1997. © 1997 Wiley‐Liss, Inc.

Inhalation of antigens may stimulate the immune system by way of the upper as well as the lower airways. We have shown that at least 1,000 times more live pneumococci were recovered from pulmonary tissue after being presented as drops of a liquid suspension onto the nares of anesthetized mice compared to the number of bacteria recovered from animals that were not anesthetized in the course of the challenge. Mice that were similarly immunized intranasally by inhalation of three different nonreplicating particulate vaccine formulations, i.e., a meningococcal outer membrane vesicle (OMV) vaccine, a formalin-inactivated whole-virus influenza (INV) vaccine, and the INV vaccine with OMVs as a mucosal adjuvant, during general intravenous anesthesia developed concentrations of vaccine-specific serum immunoglobulin G (IgG) antibodies that were four to nine times higher than in mice that were fully awake during immunizations. The concentrations of IgA antibodies in serum were also higher in anesthetized than in nonanesthetized mice and correlated positively with the corresponding levels of serum IgG antibodies in the anesthetized but not in the nonanesthetized mice. In saliva and feces, however, the concentrations of IgA antibodies were equally high whether or not the animals were dormant during immunizations. The results indicate that intrapulmonary antigen presentation, as a part of an intranasal immunization strategy, is of importance for systemic but not for mucosal antibody responses. A major portion of IgA antibodies in serum may thus be derived from nonmucosal sites.

Sixty-five healthy adult volunteers were immunized four times at 1-week intervals with an inactivated whole-virus influenza vaccine based on the strain A/New Caledonia/20/99 (H1N1) without adjuvant. The vaccine was administered as nasal spray with a newly developed device to secure intranasal delivery (OptiMist TM , OptiNose AS, Oslo, Norway), as regular nasal spray, nasal drops or as an oral spray. Significant IgA-antibody responses in nasal secretions were induced in volunteers immunized intranasally but not after oral spray immunization. In saliva, IgA antibodies were only marginally amplified even after oral spray immunizations. At least 73% of the volunteers belonging to any group of vaccine delivery reached serum haemagglutination inhibition titres of 40 or higher, considered protective against influenza, after only two vaccine doses. Those who had the vaccine delivered intranasally also showed evidence from in vitro secretion of granzyme B that cytotoxic T cells had been stimulated. Although immunization with the breath-actuated OptiMist TM device and nasal drops were superior with respect to both mucosal and systemic immune responses, oral spray immunization might still be considered for studies of mucosal adjuvants that are not yet acceptable for intranasal use.

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Mice immunized intranasally with a formalin-inactivated A/PR/8/34 (H1N1) influenza whole virus vaccine adjuvanted with cholera toxin, outer membrane vesicles from group B meningococci or formalin-inactivated whole cell Bordetella pertussis were protected against replication of the homologous virus in the nasal cavity. Only some mice were protected against clinical illness measured as weight loss and lowered body temperature. All mice immunized subcutaneously with one-tenth the intranasal vaccine dose without adjuvant were protected against clinical illness but not against local mucosal viral replication. Replicating virus was primarily found in animals with low concentrations of immunoglobulin (Ig)-A antibodies in saliva regardless of concentrations of IgG antibodies in serum. Clinical illness was seen only in those with low serum antibodies regardless of antibody levels in saliva. Nonreplicating nasal vaccines may not be sufficiently protective unless they also have a substantial influence on systemic immunity.